The Cultivation, Growth, and Viability of Lactic Acid Bacteria: A Quality Control Perspective

Raphael D. Ayivi; Asia Edwards; Deja Carrington; Alaina Brock; Albert Krastanov; Abdulhakim S. Eddin; Salam A. Ibrahim

doi:10.3791/63314

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Method Article

The Cultivation, Growth, and Viability of Lactic Acid Bacteria: A Quality Control Perspective

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DOI:

10.3791/63314

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June 16th, 2022

Raphael D. Ayivi¹^,² , Asia Edwards¹ , Deja Carrington¹ , Alaina Brock¹ , Albert Krastanov³ , Abdulhakim S. Eddin¹ , Salam A. Ibrahim¹

¹Department of Food and Nutritional Sciences, North Carolina A&T State University, Greensboro, NC, USA, ²Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina, Greensboro, NC, USA, ³Department of Biotechnology, University of Food Technologies, Plovdiv, Bulgaria

Summary

The quality control assessment of lactic acid bacteria (LAB) cultures has been confirmed as an effective way to enhance the viability and functionality of LAB strains for fermentation procedures. To buttress this assertion, we developed a protocol that elucidates how LAB cultures are activated and cultivated for fermentation and bioprocessing procedures.

Abstract

Lactic acid bacteria (LAB) are essential dairy starter cultures that are significantly employed for the manufacture of fermented dairy products such as yogurt and cheese. LAB predominantly produce lactic acid as a major end product of fermentation, and they synthesize important metabolites that impart the organoleptic characteristics of fermented food products. LAB are fastidious bacteria that thrive in many environments when adequate nutritional requirements are fulfilled. The demand for superior LAB dairy starter cultures for fermentation applications in the food and dairy industry, has resulted in the need to provide viable and active cultures for all bioprocessing operations. The development of a standard protocol for ensuring the viability and enhanced functionality of LAB cultures in the laboratory as well as dairy processing environments is thus very critical. In addressing concerns linked to resuscitating weak, stressed, and injured LAB culture cells, a protocol that vividly outlines salient steps to recover, enhance cell regeneration, and improve metabolic functionality of LAB strains is of the utmost importance. The maintenance of culture purity, functionality, and viability for LAB starter cultures is likewise critical. Therefore, adherence to a unique protocol guideline will result in the promotion of fermentation performance for many LAB strains dedicated to fermentation and biotechnology processes. As a result, the Food Microbiology and Biotechnology Laboratory at North Carolina Agriculture and Technical State University has developed a standard protocol for the activation and quality control of selected LAB strains that has resulted in highly functional and viable LAB culture strains employed for fermentation research. The adaptation and recommendation of a protocol such as this for use in the dairy and food industry will help to ensure LAB viability and functionality for many applications.

Introduction

Lactic acid bacteria (LAB) are a group of uniquely diverse bacteria that have industrial potential. Strains belonging to Lactobacillus delbreuckii subsp. bulgaricus and Streptococcus thermophilus are mostly used as dairy starter cultures for fermented dairy food products such as yogurt¹. Selected LAB strains are also classified as probiotics as they confer health benefits to humans when dosages are adequately administered². Lactic acid bacteria are also gram-positive, non-spore-forming, non-respiring but aerotolerant microorganisms that are generally characterized by the production of lactic ac....